Electric control apparatus



Filed July 16, 1940 9 Sheets-Sheet 1 I $96122 /7c?/0/Q Z 2710/! Nov. 26, 1946. I H. F. ELLIOTT 2,411,617

ELECTRIC CONTROL APPARATUS Filed July 16, 1940 9 Sheets-Sheet 2 NOV. 26, 1946. I E| |QTT 2,411,617

ELECTRIC CONTROL APPARATUS Filed July 16, 1940 9 Sheets-Sheet 3 40 fiuezzzozr' fizi/a i fliaii is. M

Nov. 26, 1946. H. F. ELLIOTT 2,411,617

ELECTRIC CONTROL APPARATUS Filed July 16, 1940 9 Sheets-Sheet 4 Nov. 26, 1946.

H. F. ELLIOTT 2,411,617

ELECTRIC CONTROL APPARATUS Filed July 16, 1940 9 Sheets-Sheet 5 Nov. 26, 1946. H.'F. ELLIOTT 2,411,617

ELECTRIC CONTROL APPARATUS Filed July 16, 1940 9 Sheets-Sheet 6 Nov. 26, 1946. 1-1. F. ELLIOTT ELECTRIC CONTROL APPARATUS 9 Sheets-Sheet 7 Filed July 16. 1940 fizz/0% fay/32??"- Nov. 26, 1946. 1-1. F. ELLIOTT v ELECTRIC CONTRQL APPARATUS Filed July 16, 1940 9 Sheets-Sheet 8 Nov, 26, 1946. H. F. ELLIOTT ELECTRIC CONTROL APPARATUS Filed July 16, 1940 9 Sheets-Sheet 9 flaw/d .57% 5 2 BY M Patented Nov. 26, 1946 UNITED STATES PATENT OFFICE 2,411,617 I ELECTRIC CONTROL APPARATUS Harold F; Elliott, Chicago, Ill. Application July 16, 1940, Serial No. 345,762

This invention relates to control apparatus and in particular toan automatic tuning system for radio receiving apparatus.

It is an object of this invention to provide an improved automatic tuning system for radio receiving apparatus. 7

A further object of this invention is to provide a physically compact tuning device, which is simple, inexpensive, efficient in operation and of preassembled unit construction.

Another object of this invention is to provide an electrical tuning system in which each of a plurality of control units for driving a rotary control shaft in operative engagement with frequency changing means, is constructed to move the frequency changing means through its entire tuning range with a relatively low driving ratio to effect a precisiontuning thereof.

Another feature of this invention is the provision of electrical tuning apparatus in which the actuating magnets are equally eflicient in either A. C. or D. C. systems without the necessity of changing the pole structures thereof; the

structure operated by the magnets being assembled in a manner to eliminate the usual chattering action of the unshaded magnets when used in an A. C. system. Similar magnets may thus be used for both' types of systems whereby to further reduce the cost of the tuning apparatus.

Yet another feature of this invention is found in the provision of a tuning unit in which the 4 Claims. (Cl. 192-142) operating parts are arranged to form an integral part of the frame means for the unit.

Another feature of this invention is the provision of a tuning device in which a manually actuated clutch unit for connecting a rotary. con-- trol unit with a motor driven driving member is arranged to close the energizing circuit of the motor after its clutching operation, whereby to immediately operate the control unit. V I

Yet another featureof this invention is the provision of control apparatus in which a rotary control shaft is rotated in either direction of rotation by a rotary control unit operated by a unidirectional motor.

A further feature of this invention is the provision of control apparatus in which each of a plurality of control units for driving a rotary control shaft to a predetermined control position is provided with an operating motor, with the motors being arranged in a common. control circuit for selective energization.

Further objects, features, and advantages of this invention will become apparent from the following specification when taken in connection with the accompanying drawings in which: I

Fig. 1 is a plan view of one embodiment of the invention with parts thereof broken away for the purpose of clarity;

Fig. 2 is an end elevational view looking toward the right as viewed in Fig. 1, with parts thereof broken away to show the driving system for the rotary control means;

Fig. 3 is a fragmentary bottom view showing the frequency changing means and its driving engagement with the rotary control means;

Fig. 4 is a fragmentary bottom view of the driving motor and its associated clutch assembly;

Fig. 5 is a fragmentary detailed sectional view of the driving end of the motor shaft;

7 Fig. 6 is a detail view, partly in section,,of the gear train for the rotary control units. This detail is illustrated as removed from the structure of Fig. 1 and rotated toward the reader sufiiciently to show the shaft and gear relationship more clearly;

Fig. 7 is a sectional view of the rotary control means showing the arrangement thereon of the rotaryv control units;

Fig. 8 shows an electric control circuit for the embodiment of Fig. 1;

Fig. 9 is an end view illustrated similarly to Fig. 2 showing a manually operated clutch unit for the rotary control units;

Fig. 10 is a fragmentary view of the clutch unit in one of its operating positions;

Fig. 11 is a view illustrated similarly to Fig. 10 showing the parts thereof in changed position;

Fig. 12 is a somewhat diagrammatic illustration of a control circuit for the tuning device of Fig. 9;

Fig. 13 is an elevational view looking toward theright as viewed in Fig. 9, with parts thereof removed for the purpose of clarity;

Figs. 14-18, inclusive, are detail showings of the clutch unit illustrated in Figs. 10 and 11; Fig. 19 is a plan view of a modified form of the invention;

Fig. 20 is an elevational view as seen along the line 20-20 in Fig. 19; I

Fig. 21 is a fragmentary sectional view as seen along the line 2 |-2 I in Fig. 19;

Fig. 22 is a view illustrated similarly to Fig. 21 showing the parts thereof in changed position;

Fig. 23 is a fragmentary detailed sectional view taken approximately along the line 2323 in Fig.22;

Fig. 24 is a fragmentary plan view of another modification of the invention;

Fig. 25 is a sectional view taken along the line 2525 in Fig. 24;

Fig. 26 is a detail view as seen along the line 2626 in Fig. 24;

Fig. 21 is an enlarged fragmentary detail view as seen along the line 21-21 in Fig. 26;

Fig. 28 is a fragmentary elevational view taken along the line 28-28 in Fig. 21 showing merely the pivoted arm and one stop;

Fig. 29 is an enlarged fragmentary detail view taken along line 2929 in Fig. 26;

Fig. 30 is a fragmentary elevational view as seen along the line 30-36 in Fig. 29 showing the pivoted arm at the stop at the opposite end of the Operating range as compared with the position of Fig. 28;

Fig. 31 is an electric control circuit for the .modified embodiment of the invention shown in Fig. 24; and

Fig. 32 is an electric control circuit for the modified embodiment of the invention shown in Figs. 19-23, inclusive.

Referring to the drawings, the preselector unit shown in Figs. 1, 3, and 4, is seen to include frame means, having end plates 2| and 22, spaced apart by lower tie rods 23 and an upper tie rod 24. A uni-directional driving motor 26 is mounted on the end plate 2| by supporting studs extended through the laminated motor field structure 21. The motor is positioned away from plate 2| by spacers 28 and secured in place by nuts 29. End 3| of the motor shaft 32 projects through the plate 2| and has mounted thereon a clutch assembly 33, which includes a steel washer 34, a spring washer 36, a pinion gear 31, a fibre friction washer 38 and an assembly retaining bushing 39. The shaft end 3|, as clearly shown in Fig. 5, is of reduced section and is formed with a flat 4| near the outer extremity thereof. The shoulder portion 42 serves as a stop or abutment for the washer 34 to define the inner position of the clutch assembly 33, with the flat portion 4| frictionally engaging the set screw 46 of the retaining bushing 39 to positively maintain the clutch assembly 33 on the-motor shaft 32. Gear 31 is in driven engagement with a gear 43 which is mounted at one end of a supporting shaft 45 for an elongated pinion .gear 44 (Figs. 1 and 2). It is contemplated that gear 43 be of fibre or other like composition material. Gear 43 rotates the shaft 45 through a spring connection with a retaining bushing 46. The looped end 41 of the coil spring 58 is connected to a friction screw 48 (Fig. l) which holds the bushing 46 in a fixed position relative to the pinion shaft 45. The opposite end 49 of the spring is hooked into an aperture formed in the face of the gear 43. The spring connection of the gear 43 to the bushing 46 thus provides a flexible drive between the motor shaft 32 and the pinion gear shaft 45 and prevents any possible freezing together of the clutch gears I I1 and 44 as will be explained later. A steel washer 52 holds the gear 44 loosely upon hub 46 so that it is free to rotate relative to the hub within the limit imposed by spring 50.

The elongated pinion gear 44 is arranged for driving engagement with gear trains 53, one of which is provided for driving each of the rotary control units 54. The units 54 are mounted on a rotary control shaft 51 which is rotatably supported in the end plates 2| and 22. A gear 58 mounted on the shaft 51 near its end 59 is in operative engagement with a condenser gear 6| which is mounted on the condenser shaft 62 (Figs. 1 and 3). The condenser 63 is supported on the end plate 22 by suitable screw means 64 or the like. Although the condenser 63 is illustrated as being a gang condenser it is to be understood that other frequency changing means may be used with equal satisfaction. The motor 26 is thus seen to be in driven engagement with the condenser 63 through the mechanism above described, the extent of condenser rotation for tuning purposes being controlled by rotation of the control shaft 51 in a manner now to be described.

The control units 54 are similarly constructed and are mounted in succession axially of the control shaft 51 (Figs. 1 and '1). Each unit inclndes a pair of similar gears 65 and 65 mounted on similar bushings 66 and 61 having annularly extending shoulder portions 68. The bushings are broached on the inside thereof in conformance with the flats 69 formed on the control shaft 51, so as to be keyed to the shaft. Gear 65 and washers 1|, three in number, are freely rotatable on the bushing 66; and gear 65' and washers 12, also three in number, are freely rotatable on the bushing 61. The washers 1| and 12 are similar, the projections 13 and 14, respectively, formed thereon extending axially toward each other. The projections 13 and 14 are of a length somewhat less than the thickness of the washers 12 and 13 so that the projections on adjacent washers only are engageable. Thus on rotation of gear 65 the projection 16 integrally formed thereon engages the projection 13 on the next adjacent washer 1|, with the projections or fingers 13 on the remaining washers 1| being successively engaged on continued rotation of the gear 65 until a coupled engagement of the gear 65 is made with the radially extending projection 11 formed on a center washer or adjustable collar member 18 arranged between the bushings 66 and 61. Rotation of gear 65' provides for a similar operation of the washers 12 into engagement with the projection 11, for a purpose to be later explained. The member 18 is normally freely rotatable on the control shaft 51. so as to be adjustable to a predetermined position in correspondence with a particular control position of the shaft. The adjusted position of the member 18 is maintained by its frictional engagement with the adjacent ends of the bush ings 66 and 61, as will be explained. The coupled engagement of both gears 65 and 65 through their respective washers 1| and 12 with the adjustable collar member 18, defines the predetermined control position of the shaft, 51, as will be later fully explained.

As shown best in Fig. 7, the portion of the control shaft 51 carrying the pinion gear 58 is of enlarged section to form a shoulder 19 on the shaft. A spacing member 8| keyed to the shaft 51 and pressed against the shoulder 19 positions the control units 54 and gear 58 away from the end plate 22 while a similar unit 82 spaces the control units and a clamping unit 88 away from the end plate 2|. In assembly, therefore, the spacers BI and 82 and units 54 are mounted on the reduced section of the shaft 51 and strung'over the length thereof in a proper assembly order prior to the positioning of the shaft in the end plates 2| and 22. Conditioning of the units 54 to provide for a predetermined positioning of the center washers 18 relative to the shaft 51 is accomplished by the two washers 83 and 84 which have a spring washer 86 located therebetween. On separation of the washers 83 and 84 the spring is released until the control members 18 for each of the units 54 are permitted to rotate under but slight pressure from the spring 86 on the shaft 51, so as to be freely movable to an adjusted position, as will be of a magnet I09.

whereby to clamp the member in the position which it has at the time, of such engagement. The clamping action of the washers 83 and 84 is controlled by manipulation of a set screw 81 (Figs.

1 and 7) which is positioned in the thrust mem ber or clamp 88. By virtue of the engagement of pin 89 in the tapered slot9I formed in the member 88, adjustment of the set screw 8! acts to move the member 88 away from or toward the control units 56 to control the action of the washers 83 and 84 on the spring 86 in a manner whic is clearly apparent. I 1

' The gears 65 and 65' are engageable with pinions 92 and 93, respectively, which are included in each of the gear trains 53 for the units 54. The pinions 92 and 93 are engageable with each other and arranged so as to rotate the gears 65 and 65' in opposite directions on turning of either thereof. The pinions 92 are axially aligned, and freely On a clamping together .of the,

other to engage opposite sides of the member .18,

rotatable on a shaft-9|; each pinion 92 (Figs.- 1

and 6) is self-spacing and is formed with a spacer portion 94 and a toothed or gear portion 96, the portion 94 being of a length to position each of the toothed portions 96 substantially opposite a gear 65 for each of the control units 54. Assembly of the pinions on the shaft 91 is maintained by a bushing 98 which is frictionally engageable with the shaft through friction screw 99. The threaded ends of the'shaft 91- are held by nuts I02 to tie plates IOI and extend through the frame end plates 2| and 22; the nuts I02 serving to hold the tie plates IOI against the pinion assembly and to space the pinions from the'end plates 2| and 22. Nuts I03 on the outside of the end plates 2| and 22 fixedly mount the shaft 91 thereon.

The pinions 93 are substantially similar to the pinions 92 and are axially aligned and freely rotatable on a shaft I04 having threaded ends which are mounted in the tie plates I 0| and the end plates 2| and 22 in a manner similar to that above described for the shaft 91. The spacer portions 95 are arranged substantially opposite the gear portions 96 of the pinions 92, andthe gear portions I00 are substantially opposite the gears 65' and engageable therewith, The shafts 97 and I04 are thus seen to be parallel to each other,

with the pinions 92 and 93 arranged substantially opposite a corresponding control'unit '54 and in engagement with the gear members 65 and 65 respectively.

Interposed between adjacent pinions 92 is a rocker arm or armature I06 for each unit 54 which is of substantially L-shape and freelyrotatable on the shaft 91. As shown in Figs. 1 and 2, the

leg portion I01 of each armature is arranged in an attractable position relative to the pole I08 The attraction of the armature I06 by the magnet I09 is opposed by a spring II I which is connected at one end to a projection I I2 formed on the armature leg portion H3, and at its opposite end to a tie rod I I4 which extends longitudinally of the pre-selector unit and is mounted in the end plates 2| and 22. Spring II I holds the armature in its normal rest or open position against the tie rod 24 which is suitably cushioned. A pinion or idling gear III isfreely rotatable on a pin II8 which is supported in the leg portion I I3, the pinion III being positioned so as to be in continuous meshing engagement with the pinion 92. Movement of the armature .through a distance defined by its angular movement between the pole piece I08 and cushioned tie rod 24 is suflicientto move the gear I" into and out of engagement with the elongated pinion 44, which, :as previously explained, iscommon to all ofthe control units54.

Each armature I06 and its associated pinion II 1 thus functions a a clutch means for engaging one of the control-units :54 .with 'theelongated pinion 44 through thegear train orpinion gears 92 and 93. The pinions 92; 93and III are always in continuous meshing engagement sothat an immediate rotation of the gears 66 and 65" is obtained on engagement of thepinion II! with the elongated pinion 44. .A fibre washer I I9 (Fig. 6) i mounted about the shaft S'Ibetween the tie plate IM and adjacent armature I06 to substantiallyeliminate any vibratoryor chattering action of this armature from being transmitted into the frame means on operation of the magnet I09 in an A. C. system. Thisvibration insulating means is the only one necessary in the entire assembly of theshaft 91' and its associated pinions 92 and armatures I06. The magnets I09 are mounted on a bracket member I23 (Fig. 1) so as tobe substantially opposite their corresponding armatures I06. Member I23 is supported on the end plates2l and 22 by suitable screw means I20 or the like. A terminal panel I24 is secured to the upperportion of the bracket I23 as viewed in Fig. 2, with the panel being suitably insulated from the bracket. Electrical connection of the magnets to the operating electrical system is thus directly made in immediate adjacence to the assembly position of the magnets in the preselector unit. 7 I

In the construction of the tuning apparatus or preselector unit as thus far described it is seen that the shafts 91 and I04, and the magnet support I23, while forming component parts of the preselector unit function also as tie rods in supporting, the end plates2I and 22 and thus coact with the tie rods 23 in providing a unit of simple and compact, but rugged design. It is seen also that the corresponding parts for each unit54 are arranged, longitudinally of the preselector unit while each control unit 54 and its component part are arranged transversely of the preselector unit.

- A relay unit I26 (Fig. 2) including operating magnets I21 and I28 for armatures I29and I3I, respectively, is included in the circuit of the magnets I09 and motor 26 and operates to control the starting and stopping of the radio receiving apparatus, as will be explained. I

As shown in the circuit. diagram in Fig. 8 the magnets I 09 are arrangedin parallel between conductors I32 and I33 which are inductively connected to a suitable supply source I34. The motor 26 which is in driving engagement with the elongated pinion 44, as was previously explained, is, connected in serie with each of the magnets I09 so as to be energized concurrently on energization of each magnet. It is thus seen 'magnet I28 attracts the armature I3I intoa locked position with an interlock member I31 so that this initial actuated position of the armature I3I is retained even after the off" switch I36 is opened. The armature I3I (Figs. 2 and 8) is provided with an arm I38 which is engageable with contacts I39 and MI, the contact I39 controlling the circuit I42 to the radio heaters and the contact I4I the rectifying circuit I43. The radio on" button or switch I44 is connected in parallel with the magnets I09 and with the off switch I36. Operation of the button I44 energizes the magnet I21 to release the interlocking member I31 from its engagement with the armature I3l. This releasing of the armature I3I moves the contacts I39 and MI in a direction to close the circuits to the radio heaters and rectifier so as to condition the radio receiving apparatus (not shown) for broadcast reception. The arrangement of the circuits shown in Fig. 8 is such that the set may also be turned on by pressing any of the tuning buttons as I35, energizing magnet I09 and motor 26. The on coil I21 is connected in parallel with motor 26 in a switch leaf I39A whenever the set is off, and so receives energywhenever the motor is energized under this condition. As soon as the latch I31 is stopped and switch I39 moves to the on position, this circuit is broken and coil I21 is deenergized.

In the operation of the preselector unit let it be assumed that the on switch I44 has been turned on. On actuation of a push button I35, which may be located remotely from the tuning apparatus, the energizing circuit for a magnet I09 is closed through conductors I32 and I33 as is also the circuit of the motor 26 which is connected in series with the magnet. Concurrently with the start of operation of the motor 26 to rotate the elongated pinion 44 through clutch means 33 and gear 43, the gear I I1 on the armature I06 is moved into engagement with the pinion 44. The motor 26 is of uni-directional type and the gear train from the motor to the elongated pinion 44 is arranged so that the pinion 44, as viewed in Fig. 2', rotates in a clockwise direction, which in turn rotates the clutch gear I I1 in a counter-clockwise direction. This direction of rotation of the pinion 44 acts to pull the gear I I1 into meshing engagement with the elongated pinion so that the gear H1 is locked in mesh during the tuning operation. Since this meshing engagement holds the armature I06 in its attracted position against the magnet pole face I08, a mechanical pressure urging the armature toward the pole face occurs concurrently with the electrical attraction of the armature by the pole face to aid the magnet in operating the clutch means I06-I I1. The magnets I09, therefore, need only be large enough to pull the clutch armature I06 into its attracted position against the pole face I08. This utilization of the mechanical reaction between the gears 44 and H1 provides for the use of relatively small magnets I09, since the magnet merely functions as a tripping means to initially engage the gear H1 and the pinion 44; the pulling of the gear II1 into meshing engagement with the pinion 44 being sufficient to maintain the geared or interlocked engagement between such gears so long as the pinion is rotating. The floating or spring connection of the fibre gear 43 to the pinion shaft 45 assures a positive disengagement between the gears 44 and I I1 on completion of a tuning operation. A torsional force is built up in the spring 50 so that when the motor 26 is deenergized the gears 44 and H1 are thrown out of mesh by the return of the spring 50 to its free untensioned position. The constantly applied mechanical pressure on the armature I06 by the operation of the gears 44 and H1 serves further to reduce the chattering action of the armature when the magnet I09 is operating in an A. C. system.

With the-pinions 92 and 93 in continuous engagement with each other and with the pinion 92 in engagement also with the gear I I1, the pinions 92 and 93 are reversely rotated so as to rotate their associated gears 65 and 65', respectively, in opposite directions on the control shaft 51. As the gears 65 and 65 are rotated their respective projections 16 and 16' and the projections 13 and 14 on the washers II and 12, respectively, are moved into successive engagement in a stepped relation as is clearly shown in Fig. 1, and as was previously fully described. Since the gears 65 and 65' are rotated in opposite directions their coupled engagement with the projection 11 on the adjustable collar member 18 occurs on opposite portions of the projection 11. The gear first to be coupled with the projection 11 rotates the control shaft 51 by virtue of the fixed position of the collar member 18 on the shaft 51, until both gears are in coupled engagement with the member 18. Since the driving force of the gears 65 and 65' act on the projection 11 in opposite directions and since these opposite forces are equal to each other, the coupled engagement of both gears with the member 18 will lock the gears against any further rotation thereof and hence of the control shaft 51. This locked engagement of the gears 65 and 65 with the member 18 de- I fines the predetermined control position of the shaft 51 and hence of the condenser 63, which is in driven engagement with the shaft 51 through gears 58 and GI, as was previously explained. Although the rotation of the motor is unidirectional the opposite rotation of the gears 65 and 65 provides for a rotation of the control shaft and hence of the condenser in either direction, the direction of rotation being dependent upon which gear 65 or 65' is first coupled to the adjustable member 18.

To adjust the various control units 54 to a predetermined control position screw 81 in the thrust mechanism 88 is Withdrawn until the center washers or adjustable collars 18 are free to turn relative to the shaft 51. Shaft 51 is then adjusted to a desired control position by a suitable manual control knob (not shown) for the frequency changing means 63. With the shaft in this position a unit 54 is operated to its locked position by pushing a button I35, while the operator holds the manual control knob and hence the shaft 51 from turning. The member 18 is thus adjusted to a predetermined control position of the shaft 51. A similar procedure is repeated for the other control units 54. During this setting operation, the members 18 are maintained in adjustment by virtue of the fact that their frictional engagement with the bushings 66 and 61 is sufficient to maintain their relative positions on the shaft 51. Spring washer 86 keeps all parts on shaft 51 always under pressure for this purpose. When all of the units 54 have been adjusted the screw 81 is tightened whereby to frictionally lock all of the members 18 in fixed positions relative to the shaft 51.

The clutch means Iu6-I I1 are readily adapted for manual actuation instead of magnetic actuation by the arrangement illustrated in Figs. 9-18, inclusive. With reference to Fig. 9 the motor 26 is illustrated in driving engagement with the clutch unit I41, whereby to operate the control unit 54 in the manner hereinabove fully described in connection with Fig. 1.

Each clutch unit I41 is comprised of a pair of flat fingers or arms I48 and I49 of unequal length, which are pivotally supported at /their ends II and I52, respectively, on the pi'nionshaft 91; the arms being assembled with ten flat sides togetherand spaced between the pinions 92 in a manner similar to that above described in connection with the armatures I86. As shown in Figs. 14 and 15 the arms III and I52'are'formed with corresponding grooves I53 and I54 which are adapted to have a continuous tension member I 56 such as a spring or the like seated therein. The member I56 functions normally to maintain the arms I5I and I52 in transverse alignment, while providing for a relative slidable movement therebetween. -The small arm I52 intermediate its ends has mounted thereon a rotary gear member I51 which is spaced from the arm I52 by a spacer I58; the spacer and gear being mounted on a pin I59 supported in the arm I52 (Figs. 16-18) Arm I48 is formed with an actuating or lever portion I6I which extends through a slot I62 formed in a panel member or bracket I63 which is supported at its ends to the end plates 2| and 22 (Fig. 13). The rotary gear member I51 is positioned on the arm I49 so as to be in continuous meshing engagement with the pinion 92. A spring I64 connected at one end to the top of the bracket member I63 and at its opposite end to the arm member I48 serves to hold the arm against the upper end or the slot I62. This limiting position of the arm I 48 holds the gear I51 out of engagement with the elongated pinion 44, since the arms I48 and I49 are normally pivotally movable together. Engagement of the rotary gear member I51 with the elongated pinion 44 to provide for a rotation of the pinions 92 and 93 is obtained by moving the lever portion I6 I downwardly in the slot I62. This engagement is normally completed while'the pinion is in an idle or stationary position. The slot 62, however, is of a length to provide for a continued downward movement of the lever I6I, after engagement of the gear I51 with the pinion 44, to permit its engagement witha switch or gate plate I66, which extends longitudinally of the frame means 20 and is pivotally supported as at I61 to the end plates 2| and 22. A contact I68 is provided on the lower side of the switch plate I66 and is ar ranged for engagement with a contact arm I69, the closing of these contacts efiecting a closing of the motor circuit and a consequent operation of the motor 26. Downward movement of the lever I6l thus functions both to move the gear I51 into its engaging position with the pinion gear 44 and also to close the circuit of the motor 26 to operate the pinion 44. The switch plate I66 is normally tensioned bysuitable spring means (not shown) so as to keep open the contacts I68 and I69. As shown in Fig. 12 the motor circuit is inductively connected with a suitable source of electric supply such as I16 and includes conductors HI and I12 connected in series with the motor 26. Conductor I1I is connected with contact I68 through the switch plate I66 and conductor I12 is connected to the contact arm I69.

As previously mentioned, the motor 26 is of unidirectional type and is in driven engagement with I66 to swing upward to open the contacts I68 and I 1 the-gears 31 and 43 in a anner to provide for a inion 44 as viewed in clockwise rotation of the fi Fig. 9. This direction of rotation of the pinion '44, after engagement thereof with the rotarygear I51,-serves to mechanically i terlock the gear I 51 with the pinion 44 even after release of the lever portion I6I. However, since the lever I6I directly controls thecircuit of the motor 26, as above explained, it is readily apparent \that this interlocked engagement of the gears after release of the lever I6I would result in a continued energization of the motor circuit. In the movement of the lever I6I into engagement with the switch plate I 66, the engagement of the gear I51 with the pinion 44 prior to a, closing of the motor circuit serves to maintain the arm I49 in a held position while the arm I48 is moved intoits motor operating position. This relative pivotal movement between the arms I 48 and I49 occurs by virtue of the tension means I56. On release of the lever I6I, thespring means I56 permits the lever I6I to be pulled upward by spring I64 to permit'the gate I69, as shown in Fig. 11, whereby to deenergize the motor 26. On deenergization of the motor the torque on pinion 44 ceases and hence the rotary gear I51 is released, the clutch unit I41 bein im-- mediately returned to its idle position by the spring I64. A cushion spring 50 interconnecting gear 43 and hub 46 provides a kick back action to assure release of gear I51 from pinion 44 as already described.

In some instances it may happen that the gear I51 will not immediately mesh with the pinion 44 because of an abutting rather'than a meshing engagement of the gear teeth, as indicated in Fig. 10. The arm I49 is thus held in a position above that normally attained on a meshing engagement of the gears 44 and I51. Should this occur the flexible connecting means I56 between the arms I48 and I49 permits the arm I48 to be moved into its engaging position with the switch plate I66 to close the contacts I68 and I69, this'relative positioning of the arms I48 and I49 being shown in Fig. 10. Immediately on closing or the contacts I68 and I69 the pinion 44 is rotated by the motor -26, this rotation of the pinion 44 breaking the abutting engagement of the teeth portions, as indicated in Fig. 10, and permitting a, meshing engagement between the rotary gear I51 and the pinion 44 as shown in Fig. 9. Since the operation of the tuning apparatus illustrated in Figs. 9 to 18, inclusive, is similar to that previously described in connection with Fig. 1 except for the manually actuated clutch unit I41, it is believed that a, further description of the operation is unnecessary.

It has been noted that three washers 1| and three washers 12 are used in each of the control units 54. The number of washers, however, may be changed in accordance with a particular tuning structure, a larger number of washers providing for an increased driving ratiobetween the control unit 54 and shaft 51. This drivingratio provides for a relative free motion of the gears 65 and 65',

between their locked positions, which is comm'ensurate to the driving ratio between the shaft 51 and condenser shaft 62. A free motion of this degree in each unit 54 conditions each unit to move the condenser through its complete tuning range, which in the case of the usual gang condenser is a movement of about It is readily apparent, therefore, that as the driving ratio between the rotary control shaft 51 and condenser '63 is increased, the accuracy of the control unit 54 in moving the shaft 51 to a predetermined con- 11 trol position is increased, since the error of tuning is decreased in proportion to the increase in the driving ratio. In other words, the angular displacement ofthe condenser 63 is only a predetermined portion of that of the shaft 51, for any tunin operation, In the embodiment of Fig. 1, a driving ratio of about 3 :1 between the shaft 51 and condenser 63 has been found to give very satisfactory tuning results. Where a connection such as a flexible cable is used as a mechanical transmission means between a control knob and a condenser an appreciable angular displacement occurs in the cable so as to impai the precision of the tuning operation. In one commercial embodiment of the invention a driving ratio of 12:1 has been satisfactorily employed to reduce the degree of error in the tuning resulting from the use of a flexible cable.

A modification of the invention permitting 12 free revolutions of each of gears 65 and 65' is shown in Figs. 19-23, inclusive. This modification of the invention is similar in many respects to the embodiment shown in Fig. 1 and similar numerals of reference, therefore, will be used to designate similar parts.

The driving motor 26 is in driving engagement with the pinion assembly including pinions a, through clutch assembly 33 and gear 43, the pinion assembly in turn being connected with the pinion gear trains 53 by the clutch means I06'I I1, formed with opposed flat portions I13 for keyed engagement with the pinions 44A, mounted on the shaft 45', which are internally formed with mating fiat portions, there being a pinion A for each control unit 54'. Armatures I66 are rotatably supported on the shaft 45' and arranged between adjacent pinions A, Each pinion 44A is in continuous engagement with a pinion II1' which is freely rotatable on a pin I I8 mounted in the armature I06. The armature is attractable by a magnet I09, the magnets being vertically arranged in the unit as shown in Figs. 21 and 22. The action of magnet I09 on its corresponding armature I06 is opposed by the action of a spring III which is connected at one end to a projection I I2 and at its opposite end to a tie rod or rail I I4 supported between the end plates 2| and 22. The armature I 06' in its open position is held by the spring III against a nonmagnetic rest rail II6' which is also mounted between the end plates 2| and 22, A brass stop or magnetic separator S (Figs. 21 and 22) is secured to the armature I06 in a position such that it engages the core of the magnet I89 when the armature is attracted thereto, so as to eliminate any possibility of the armature freezing to the magnet.

The pinions 92 and 93 are engageable with gears I65 and I65 of the control units 54', respectively. Besides the gears I65 and I65 each unit 54' includes an adjustable collar member 18' and a pair of sleeve members I14. The flat portions 69 formed on the shaft 51' are adapted for keyed engagement with corresponding broached fiat portions formed internally of the sleeve members I14. Each sleeve member I14 is formed with an enlarged section and areduced section, the reduced section I16 being adapted to have a gear I65 or I65 freely fully rotatable thereon. It is thus seen that although the sleeve members I14 are keyed relative to the shaft 51', that the gears I65 and I65 are freely rotatable relative to the shaft 51'.

In the assembly of each control unit 54', which The shaft 45 (Figs. 21 and. 22) is are of similar construction, the sleeves I14 are arranged with their reduced sections I16 facin each other and with the adjustable member 18' positioned between such facing portions. Since the mounting portion on each member I14 for the gears I65 or I65 is of a greater length than the thickness of such gears, the pressing together of the control units during their assembly on the control shaft 51' does not bind the gears I65 and I65 relative to the shaft 51' but serves merely to frictionally engage the adjustable member 18' between each pair of sleeve members I14, The frictional engagement of the member 18' in a particular adjusted position corresponding to a predetermined control position of the shaft 51' is obtained by manipulation of the clamping mechanism 88, previously explained.

The adjustable collar member 18 is formed with a radially extending abutment I11 of rounded gear tooth contour. This abutment is formed and arranged so as to be engageable with pinions I16 and I18 which are rotatably supported on pins I19 and I19 mounted in the face portion of each gear I65 and I65, respectively. In the assembly of each pinion I18 and I18 a spring washer I8I (Fig. 23) is arranged on the pin I19 between the pinion and the pin head I82 so as to effect a slight drag or frictional pressure on the pinion. This pressure is just enough to prevent the pinions I18 and I18 from moving out of a meshing position with the abutment I11 on rotation of the gears I65 and IE5. The toothed contour of each of the pinions I18 and I18 is formed with a blank portion I83 which is equivalent substantially to the width of two gear teeth. With the adjustable collar member 18 fixed relative to the control shaft 51', and the shaft 51' in a stationary position, it is seen that each complete rotation of gear I65, as shown in Figs. 21 and 22, rotates the pinion I18 about the pin I19 a distance equal to one tooth, by reason of its engagement with the projection I11 on the member 18'. The progressive rotation of the pinion I18 about the pin I19 continuesuntil the portion I83 engages the tooth I11, this coupled engagement serving to lock the member 18 and the gear I 65 relative to the shaft 51' so that any further rotation of the gear I65 also rotates the shaft 51'.

With the pinions 92 and 93 in continuous engagement with each other and arranged to rotate the gears I65 and I65 in opposite directions the blank portions I83 on the pinions I18 and I18 will engage opposite sides or portions of the tooth I11. A locked engagement, therefore, of each pinion I18 and I18 with the tooth I11 thus locks the ears I 65 and I65 relative to the control shaft 51, this locked engagement defining the predetermined control position of the shaft 51'. The gear I65 or I65 first engaged in a coupled connection with the adjustable member 18' by the locking action of its associated pinion with the tooth I11 serves to rotate the shaft 51 in a given direction until a position is reached which brings about a coupled connection between the member 18' and the uncoupled gear, thus looking both gears I65 and I65 against any further rotation.

Although the pinions I18 and I18 are indicated as providing for a relative rotational movement of six revolutions between the gears I65 and I65 to correspond with a desired 12:1 driving ratio between the control shaft 51 and condenser 63', it is to be understood that the gears I65 and I65 and pinions I18 and I18 can be altered in size to provide for a wide variation of the free motion in the control unit 59.

The structure of each control unit fl' provides 91 I Fig. 1. A very compact and highly efficient tuning apparatus is .thus provided which isareadily applicable to a variety of tuning requirements.

Theoperation of embodiment in Figs. 19-23,

is substantially similar to the operation of the embodiment of Fig. 1; the circuit diagram-of Fig.

32 being applicable. On energization of a mag-v net I09' by a push button I95 the motor 26 is also energized through the double set of contacts H and 0' whereby the pinion assembly 44' is rotated substantially simultaneously with the actuation of the clutch means I08'-II1'. That is, upon pushing a button I35, the corresponding magnet I09 is first energized by engagement of button contact with battery contact 0'. Continued pressure upon the button brings the contact 0' into engagement with motor contact H0. The contacts IIO' are in a common circuit. The pinion assembly 44 is arranged to rotate in a counterclockwise direction, as viewed in Figs. 21 and 22, so as to rotate the pinion H1 in a clockwise direction. This direction of rotation of the pinion assembly 44' aids in bringing the pinion 93 and gear 1' into meshed engagement. Since the mechanical action of the pinions A and 93 aids the operation of the magnets I09 in effecting the meshed engagement only relatively small magnets I09 are needed. Rotation of the pinion gears 92 and 93 to oppositely rotate the control unit gears I55 and I 65 actuates the pinion or coupling means I18 and I18 to couple the gears I65 and. I85 with the adjustable member 18. On rotation of the pinions I18 and I18 into their respective locked positions relative tothe tooth I11, the gears I85 and I85 are locked on the control shaft 51', the controlshaft 51' being rotated to its predetermined control position prior to such locking engagement in the manner previously explained. In practice the push button I35 may be held closed until the shaft 51' has turned the condenser 83 to its predetermined tuning position. Y

The adjustment of the members 18' to a desired setting of the control shaft 51- is obtained in a manner similar to that previously described for the members 18 in Fig. l the frictional looking of the members 18' being controlled by the cooperative action of the clamping mechanism 88 and the releasable spring 86 positioned between the washers 83 and 84.

Yet another modification of the invention is illustrated in Figs. 24-31, inclusive. As shown in Fig. 24 this embodiment includes a stationary or fixed shaft I88 which is mounted in end plates I81 and I88. A rotary control or drive shaft I89 for a frequency changing means (not shown) is arranged parallel with the shaft I88 and is rotatably supported in the end plates I81 and I88. A pair of gears I 9I and I92 for each control unit I99 are freely rotatable on the stationary shaft I88. Each adjacent pair of gears I9I and I92 are separated 'by spacers I94 while the gears HI and I 92 in each pair are separated by spacers I95. Spacers I94 and I96 are'also freely rotatable on the shaft I 88 so as not to interfere in anyway on"a-'shaft I98."' A mranty motors I99 are provided,- one for eachbontrolunit I92I tojdrlve "the gear I91 therein, the stationary shaft l98,

' and motors l99 being at-ran ed below and bef-tween the shafts I8 8 an'd I89," The shaft I98;is ,Darallel with 'the' shafts I88 and I89 'and'is suitably supported in the frame means for the tuning apparatus. The rotors I91Aof the motors rotate onfshaft I98 which may be'statio'nary'. j 10 1 Each driving gear-191 i.'=.' also in"engagenient witha gear 20I whioh' isf freelyfrotatable on a sleeve or bushing 202" mounted on'and' splined with the rotary drive shaft I89. The gear 20I is in operative engagement with an adjustable element 203 of gear form, by means of a coupling unit 204, to be later explained. The adjustable element 203 is normally adjustably fixed on the shaft I89 and is in continuous engagement with the gear I 92 mounted on the shaft l88. The

spacer or bushing member 202 is formed with a shoulder portion 206 and a reduced section for carrying the gear 20I. A spacer 201 is mounted on the reduced section of the bushing 202 between the gear 20I and the adjustable element 203. The gear 20I and element 203 of each control unit I93 is separated from the next adjacent control unit by spacers 208, the control units adjacent the end plates I81 and I88 being separated therefrom by collar or spacer members 209. Ad'- justment of the element 203 in a fixed position relative to the control shaft I89 is accomplished b its frictional engagement between the reduced section of the bushing 202 and one end of a spacer member 208, as is clearlyindicated in Fig. 24. The frictional pressure on the adjustable elements 203 is controlled by the clamping unit 89 and the spring washer unit 8386, which were I hereinabove fully described.

As shown in Figs. 26-30, inclusive, each adjustable element 203 is press formed with a corrugated face portion 2 which is spirally arranged to provide for the traversal thereof of a lever or traversing arm 2I2, which is pivotally supported on the face of gear MI. The arm 2I2 is formed with a pointed follower 2I5 which rides in the spiral corrugations of the portion 2I I. It is to be understood that this corrugated structure is applicable to all of the adjustable elements 203 indicated in Fig. 24, it being apparent that this structure could not be readily shown in Fig. 24 because of the comparative size thereof. As illustrated in Fig. 25, each of the gears I92 is also formed with a corrugated face portion 2| I' of spiral arrangementwhile each of the corresponding gears I! is provided with a pivotally supported traversing arm 2I2. The travel of the traversing arm 2I2, in one directionof rotation of the gear 20 I ,is limited by an inn-"r abutment Or stop 2I3 while the limit of its travel in the opposite direction is defined by'an outer abutment 2, the abutments 2I3 and 2 .being integrally formed in the adjustable element 203 by bumping out portions thereof. The travel of the traversing arm 2I2 is similarly defined by abutment members 2l3 and 2", which are integrally formed in the gears I 92. I

on rotation of a driving gear I91 there occurs a rotation of the gears I 9I and .20I, to provide with the free rotation of the gears I!" and I 92. r

Each gear I! is in meshing engagement with a motor driven driving gear I91 which is mounted for a traversal of the arms 2I2,' 2I2] over the corrugated portions 2 and 2| I' of the gears 203 and I92, respectively. The gears I9I and MI are rotated in the same dir ect'ion since they are both driven by the same rotating gear I91. Gear I92 will remain in a stationary or idle position until coupling engagement thereof with the gear Isl occurs by the abutting engagement of the traversing arm 2I2' against one of the abutments 2I3' or 2". When thisengasement occurs the gear I92 will be rotated in the direction of rotation of gear I9I. By virtue of this driving engagement and the continuous meshing engagement of the gear I92 with the adJustable element 203, the element 203 will be rotated to drive the rotary control shaft until the traversing arm 2I2 engages one of the abutments 2I3 or 2. The continuous engagement of the gears I92 and 203 provides for opposite relative rotation of these two gears. On the occurrence of a stopped engagement of both of the traversing arms 2I2 and 2I2' the adjustable element 203 and its associated gears I9I, I92, and I are locked in fixed positions relative to the shafts I96 and I89, which locked position defines a predetermined control position of the drive shaft I89.

It is to be understood that the adjustable element 203 is not always rotated by the gear member I92 since a coupled engagement between the gear 20I and the element 203 might occur before a coupled engagement between the gears I9I and I92, in which case the gear I92 will be rotated by the adjustable gear or element 203 and the coupled engagement of the gear 20I and element 203 will provide for the rotation of the control shaft I89 to its predetermined control position, prior to the locking of the gears I92 and 203. It is to be understood further that the amount of relative free motion of the gears before looking is readily provided by varying the extent of the spiral portions 2H and 2. The control units I93 are thus readily adapted to be made in con- 'formance with a particular driving ratio between the rotary control shaft I09 and its associated frequency changing means (not shown).

A control circuit for the embodiment of Fig. 24 is shown in Fig. 31. The motors I99 for each control unit I93 are arranged in parallel between conductors 2I6 and 2", which are inductively connected to a suitable source of electrical supply 2I9. The radio receiving apparatus (not shown) is conditioned for operation by the on" switch 2I9 and the oil switch 22I, which control the energization of the radio circuits through relay coil I21 and I28as in Fig. 8. A muting relay, including magnet 220 and armature 220', is indicated at 222. With the radio set turned on a push button 223 which may be remotely located is closed. The corresponding individual motor I99 is immediately energizedwhereby gear- I9'I is driven to operate the control unit I93 in' the manner above fully described. Since the tuning operation is of very short duration, the Z push button 223 is held closed manually for the duration thereof.

In the adjustment of the control members 203 the clamping unit 88 is released so that all of the control elements 203 are free to turn on the control shaft I39. The control shaft I 89 is then rotated to a predetermined control position and held in such position while a control unit I93 is- 16 which are within the full intended scope of the invention as deiined by the appended claims.

I claim:

1. Electrical rotary control apparatus adapted to be operated to predetermined stop positions including in combination unidirectional rotary driving means, reversibk: rotary driven means, and a lurality of rotary coupling units operatively connecting said two means and aligned axially relatively to one another in said apparatus, each of said plurality of rotary coupling units having movable interconnected structure including a driving rotary gear portion, rotatable toothed reversing means operatively connected with the driving rotary gear portion, and means including adjustable means and lost motion means operatively connecting said reversing means and said reversible rotary driven means, with all of the movable structure in each coupling unit interconnected in a manner so that such structure always moves to the same relative position at each predetermined stop position for the apparatus.

2. Electrically driven rotary control means including in combination, rotary driving means having motor means and a rotary ear portion, a rotary shaft, a rotary control unit corresponding to said rotary gear portion, said control unit including a. member on said rotary shaft and gear-toothed means including a pair of rotating gears, lost motion coupling means operatively connecting the member and said pair of rotating gears, with said rotary gear portion being in meshing engagement with gear teeth in said control unit, and means for selectively operating the rotary gear portion and the rotary control unit. 3

3. Electrically driven rotary control means including in combination a rotary driven shaft, a. plurality of rotary control units each including a pair of gears oppositely rotatable relative to one another and including an engaging member, with said engaging member and at least one of the oppositely rotatable gears mounted on said rotary driven shaft, rotary shaft means having gear means thereon operatively connected with said pair of gears and said pair of gears being relatively and oppositely rotatable upon rotation of said shaft and gear means, rotary drive means, means including said. plurality of control units operatively connecting said rotary drive means and said rotary driven shaft and said means additionally including a plurality of rotary gear ortions corresponding to said plurality of control units and each gear portion operatively meshingly connected with a rotary gear member in the corresponding control'unit, and means for selectively operating a rotary gear portion and its corresponding rotary control unit.

4.. Control apparatus including in combination supporting means, a driven member rotatable relative to the supporting means, two driving members journalled for opposite rotation relative to one another and for rotation relative to the supporting means and the driven member, lost motion coupling means coupling the driven and the driving members, rotary means journalled for rotation relative to the supporting means and interconnecting the driving members, and selectively operable means including a rotary member for providing a. driving force for the driving members for accomplishing rotation of said driving members and said driven member to a predetermined position relative to the supporting means.

HAROLD F. ELLIO'I'I. 

